The present invention relates to a method of operating an apparatus for the sterilization of containers, and in particular of plastics material containers, as well as to a corresponding apparatus for the sterilization of plastics material containers. Methods and apparatus of this type have long been known from the prior art. Whereas it was usual in the past to carry out a sterilization of this type by the use of chemical substances, such as for example hydrogen peroxide or peracetic acid, attempts have been made in recent years to reduce the use of chemicals of this type. Methods are therefore also known from the prior art in which plastics material containers are sterilized by irradiation, for example by irradiation with X-ray or UV radiation, or recently also by irradiation with charge carriers, such as in particular electrons.
A difficulty in this case is, in particular, the internal sterilization of containers, i.e. the sterilization of the inner wall of plastics material containers of this type. To this end, it is known for radiation fingers to be introduced into the interior of plastics material containers of this type and for the inner wall of the plastics material containers to be acted upon with the electrons there.
For this purpose, apparatus of this type have electron generation devices or charge-carrier generation devices and usually also acceleration devices which accelerate these charge carriers—in particular inside a vacuum chamber—in the direction of an outlet window. The charge carriers in turn can emerge through this outlet window which may be for example a titanium window. In prolonged operation of radiation apparatus of this type, however, it was found that the radiation apparatus are subjected over time to drops in performance.
The object of the present invention is therefore to provide possibilities which maintain the performance of radiation fingers of this type even over prolonged periods of time.